Fix bugs listed by clang's static analyzer

A few pedantic changes and unused variables (1-4), and genuine bugs (5,
6).

The reports with the corresponding files and lines numbers are as
follows.

1. backend/libinput/tablet_pad.c@31,44,57
"Allocator sizeof operand mismatch"
"Result of 'calloc' is converted to a pointer of type 'unsigned int',
which is incompatible with sizeof operand type 'int'"

2. types/tablet_v2/wlr_tablet_v2_pad.c@371
"Allocator sizeof operand mismatch"
"Result of 'calloc' is converted to a pointer of type 'uint32_t', which
is incompatible with sizeof operand type 'int'"

3. types/wlr_cursor.c@335
"Dead initialization"
"Value stored to 'dx'/'dy' during its initialization is never read"

4. rootston/xdg_shell.c@510
"Dead initialization"
"Value stored to 'desktop' during its initialization is never read"

5. types/tablet_v2/wlr_tablet_v2_pad.c@475
"Dereference of null pointer"
"Access to field 'strips' results in a dereference of a null pointer
(loaded from field 'current_client')"

The boolean logic was incorrect (c.f. the check in the following
function).

6. examples/idle.c@163,174,182
"Uninitialized argument value"
"1st function call argument is an uninitialized value"

If close_timeout != 0, but simulate_activity_timeout >= close_timeout,
the program would segfault at pthread_cancel(t1).

1 files changed, 14 insertions, 7 deletions

diff --git a/examples/idle.c b/examples/idle.c
index 30e106db..87a03924 100644
--- a/examples/idle.c
+++ b/examples/idle.c
@@ -152,14 +152,20 @@ int main(int argc, char *argv[]) {
 		.display = display,
 	};
 
-	if (simulate_activity_timeout != 0 && simulate_activity_timeout < close_timeout) {
+	bool create_t1 = (simulate_activity_timeout != 0) &&
+	                (simulate_activity_timeout < close_timeout);
+
+	if (create_t1) {
 		if (pthread_create(&t1, NULL, &simulate_activity, (void *)&arg) != 0) {
 			return -1;
 		}
 	}
-	if (close_timeout != 0) {
+
+	bool create_t2 = (close_timeout != 0);
+
+	if (create_t2) {
 		if (pthread_create(&t2, NULL, &close_program, (void *)&arg) != 0) {
-			if (simulate_activity_timeout != 0) {
+			if (create_t1) {
 				pthread_cancel(t1);
 			}
 			return -1;
@@ -170,18 +176,19 @@ int main(int argc, char *argv[]) {
 	fprintf(stdout, "waiting\n");
 
 	if (pthread_create(&t3, NULL, &main_loop, (void *)display) != 0) {
-		if (simulate_activity_timeout != 0) {
+		if (create_t1) {
 			pthread_cancel(t1);
 		}
-		if (close_timeout != 0 ) {
+		if (create_t2) {
 			pthread_cancel(t2);
 		}
+		return -1;
 	}
 
-	if (simulate_activity_timeout != 0) {
+	if (create_t1) {
 		pthread_join(t1, NULL);
 	}
-	if (close_timeout != 0) {
+	if (create_t2) {
 		pthread_join(t2, NULL);
 	}
 	pthread_cancel(t3);